Correct. The larger side (3.375" x 3.375") is too large for the Ts. It's almost too easy to solve (5 year old level). The other side is the challenge (2.875"). Feel free to reduce the large box down to something slightly larger than 3.125". Note that dimensions shown in step 12 show that solution at 3.127". If you have already built to the dimensions, I suggest going to the more advance version shown in step 13. This version makes good use of the 3.375" side.

Interesting project and nice job on the build. My one critique is the video. To me, it was hard to follow. I suggest reshooting it with a tripod...fire the cameraman :). I would also suggest backing out so we can see the math problem on the board at all times and work out a concise script ahead of time.Thanks for sharing.

Nice write-up! As for Step 5 (sharing your work), I recall this topic was brought up in the forums about a month ago and the gist of the argument was that people with large social media presence had an advantage in contests. I don't think it hurts but I feel the featuring guidelines you posted are way more important. I share my projects with a small group of family & friends and link to multiple forums and CAD sites. Each upload has a link back to instructables for more information.

Thanks. Yeah, I wasn't sure what he was asking. I get a decent amount of request to convert all the units to metric. I don't do it but I provide a conversion factor for those willing to go that route.Also, I usually start with wood with imperial size (1/2", 3/4", etc.). To keep things simple for me, I keep the imperial system throughout. BTW, I have to work with both units in my job. With that said, I would love for the US to convert fully to metric.

Thanks. No restrictions but i think the new website rollout made it harder to find. Scroll down a little. You will see icons appear on the top right of the screen. Click on the 3 dots. Next, click "add to collection". Yep, it's intuitive :).

Thanks. The length of the notch was arbitrary. The angle (100.5 degrees) was calculated as shown in step 5. I practiced on a scrap piece of wood and did a fit check. After that, I copied the notch onto the others boards and made the cuts.

That's just how the math turned out...dimensions from CAD. You don't need to be that precise but it looks nicer the closer you get. I've started using calipers on some of my other puzzles that require tight fits. For fine tuning, I run the piece across a sanding block.

Thanks. I have low end tools but they are better than hand cuts. It would definitely be challenging to make all the blocks and get a tight fit. I could send you the STL files if you have access to a 3D printer.

Nice job! At first glance, I thought you used a 4" thick slab of wood. I was like, wow, that looks heavy. Another option for support in lieu of wires is bottom gussets.

At first glance, I thought you used a 4" slab of wood. I was like, damn, that thing is got to be heavy. I actually like how it looks. Another option would be to add gussets to the bottom and scrap the wire.